kernel: backport patch making bcm47xxsflash arch independent

This will be needed to use bcm47xxsflash on ARM for BCM53573.

Signed-off-by: Rafał Miłecki <zajec5@gmail.com>

SVN-Revision: 49168

target/linux/generic/patches-4.4/042-mtd-bcm47xxsflash-use-ioremap_cache-instead-of-KSEG0.patch

@@ -0,0 +1,138 @@
+From 5651d6aaf489d1db48c253cf884b40214e91c2c5 Mon Sep 17 00:00:00 2001
+From: Brian Norris <computersforpeace@gmail.com>
+Date: Fri, 26 Feb 2016 11:50:28 +0100
+Subject: [PATCH] mtd: bcm47xxsflash: use ioremap_cache() instead of
+ KSEG0ADDR()
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+Using KSEG0ADDR makes code highly MIPS dependent and not portable.
+Thanks to the fix a68f376 ("MIPS: io.h: Define `ioremap_cache'") we can
+use ioremap_cache which is generic and supported on MIPS as well now.
+
+KSEG0ADDR was translating 0x1c000000 into 0x9c000000. With ioremap_cache
+we use MIPS's __ioremap (and then remap_area_pages). This results in
+different address (e.g. 0xc0080000) but it still should be cached as
+expected and it was successfully tested with BCM47186B0.
+
+Other than that drivers/bcma/driver_chipcommon_sflash.c nicely setups a
+struct resource for access window, but we wren't using it. Use it now
+and drop duplicated info.
+
+Signed-off-by: Brian Norris <computersforpeace@gmail.com>
+Signed-off-by: Rafał Miłecki <zajec5@gmail.com>
+---
+
+--- a/drivers/bcma/driver_chipcommon_sflash.c
++++ b/drivers/bcma/driver_chipcommon_sflash.c
+@@ -146,7 +146,6 @@ int bcma_sflash_init(struct bcma_drv_cc
+ 		return -ENOTSUPP;
+ 	}
+ 
+-	sflash->window = BCMA_SOC_FLASH2;
+ 	sflash->blocksize = e->blocksize;
+ 	sflash->numblocks = e->numblocks;
+ 	sflash->size = sflash->blocksize * sflash->numblocks;
+--- a/drivers/mtd/devices/bcm47xxsflash.c
++++ b/drivers/mtd/devices/bcm47xxsflash.c
+@@ -2,6 +2,7 @@
+ #include <linux/module.h>
+ #include <linux/slab.h>
+ #include <linux/delay.h>
++#include <linux/ioport.h>
+ #include <linux/mtd/mtd.h>
+ #include <linux/platform_device.h>
+ #include <linux/bcma/bcma.h>
+@@ -109,8 +110,7 @@ static int bcm47xxsflash_read(struct mtd
+ 	if ((from + len) > mtd->size)
+ 		return -EINVAL;
+ 
+-	memcpy_fromio(buf, (void __iomem *)KSEG0ADDR(b47s->window + from),
+-		      len);
++	memcpy_fromio(buf, b47s->window + from, len);
+ 	*retlen = len;
+ 
+ 	return len;
+@@ -275,15 +275,33 @@ static void bcm47xxsflash_bcma_cc_write(
+ 
+ static int bcm47xxsflash_bcma_probe(struct platform_device *pdev)
+ {
+-	struct bcma_sflash *sflash = dev_get_platdata(&pdev->dev);
++	struct device *dev = &pdev->dev;
++	struct bcma_sflash *sflash = dev_get_platdata(dev);
+ 	struct bcm47xxsflash *b47s;
++	struct resource *res;
+ 	int err;
+ 
+-	b47s = devm_kzalloc(&pdev->dev, sizeof(*b47s), GFP_KERNEL);
++	b47s = devm_kzalloc(dev, sizeof(*b47s), GFP_KERNEL);
+ 	if (!b47s)
+ 		return -ENOMEM;
+ 	sflash->priv = b47s;
+ 
++	res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
++	if (!res) {
++		dev_err(dev, "invalid resource\n");
++		return -EINVAL;
++	}
++	if (!devm_request_mem_region(dev, res->start, resource_size(res),
++				     res->name)) {
++		dev_err(dev, "can't request region for resource %pR\n", res);
++		return -EBUSY;
++	}
++	b47s->window = ioremap_cache(res->start, resource_size(res));
++	if (!b47s->window) {
++		dev_err(dev, "ioremap failed for resource %pR\n", res);
++		return -ENOMEM;
++	}
++
+ 	b47s->bcma_cc = container_of(sflash, struct bcma_drv_cc, sflash);
+ 	b47s->cc_read = bcm47xxsflash_bcma_cc_read;
+ 	b47s->cc_write = bcm47xxsflash_bcma_cc_write;
+@@ -297,7 +315,6 @@ static int bcm47xxsflash_bcma_probe(stru
+ 		break;
+ 	}
+ 
+-	b47s->window = sflash->window;
+ 	b47s->blocksize = sflash->blocksize;
+ 	b47s->numblocks = sflash->numblocks;
+ 	b47s->size = sflash->size;
+@@ -306,6 +323,7 @@ static int bcm47xxsflash_bcma_probe(stru
+ 	err = mtd_device_parse_register(&b47s->mtd, probes, NULL, NULL, 0);
+ 	if (err) {
+ 		pr_err("Failed to register MTD device: %d\n", err);
++		iounmap(b47s->window);
+ 		return err;
+ 	}
+ 
+@@ -321,6 +339,7 @@ static int bcm47xxsflash_bcma_remove(str
+ 	struct bcm47xxsflash *b47s = sflash->priv;
+ 
+ 	mtd_device_unregister(&b47s->mtd);
++	iounmap(b47s->window);
+ 
+ 	return 0;
+ }
+--- a/drivers/mtd/devices/bcm47xxsflash.h
++++ b/drivers/mtd/devices/bcm47xxsflash.h
+@@ -65,7 +65,8 @@ struct bcm47xxsflash {
+ 
+ 	enum bcm47xxsflash_type type;
+ 
+-	u32 window;
++	void __iomem *window;
++
+ 	u32 blocksize;
+ 	u16 numblocks;
+ 	u32 size;
+--- a/include/linux/bcma/bcma_driver_chipcommon.h
++++ b/include/linux/bcma/bcma_driver_chipcommon.h
+@@ -585,7 +585,6 @@ struct bcma_pflash {
+ #ifdef CONFIG_BCMA_SFLASH
+ struct bcma_sflash {
+ 	bool present;
+-	u32 window;
+ 	u32 blocksize;
+ 	u16 numblocks;
+ 	u32 size;